An Anthropological Perspective on the Sudden Infant Death Syndrome: A Testable Hypothesis on the Possible Role of Parental Breathing Cues in Promoting Infant Breathing Stability, Part I

Article excerpt

ABSTRACT: This research model moves from a comprehensive review of SIDS research to a consideration of the evolution of human infant development and why we should expect to find that especially in the first year of life, parent-infant sleep contact asserts a significant physiological regulatory effect on the infant's breathing. Prenatal studies of fetal hearing and breathing are reviewed and used to argue that the central nervous system is at birth already sensitized to parental breathing rhythms to which the infant in its "expected" postnatal environment will have access. This perspective shows that important continuities exist between fetal experiences and infant respiratory behavior. Emerging from an integration of clinical, experimental, and developmental studies with an evolutional perspective (which includes cross-species and cross-cultural data) it is hypothesized that access to parental sensory breathing cues (movement, sound, touch, and expelled CO2) ought to help one of many subclasses of infants to override breathing control errors, some of which may be involved in SIDS.

This model and the testable hypotheses which emerge from it do not suggest that parent-infant cosleeping necessarily should be recommended, or that it is always safe for the infant; only a careful analysis of the entire constellation of family attributes can determine this. Rather, the paper argues that for some infants certain CNS deficits suspected to be involved in SIDS may interact with nocturnal separation from parental breathing cues (a novel experience for our species) to increase crib death risk and, thus, must be considered as one of the many aspects in the unfolding pathophysiology of SIDS for some victims. This model is offered not as a substitute for the traditional SIDS research model which assumes the primacy of internal breathing control mechanisms, but as a complementary research approach-one in which both internal and external (environmental) factors are thought to interact to affect breathing behavior. This interactional model is justified by a variety of data revealing that aspects of parent-infant physiological synchrony are best understood in terms of the four million years in which parent-infant contact was almost certainly continuous for the infant during the first year of life wherein a high degree of postnatal immaturity is characteristic.

INTRODUCTION

I suspect that many negative findings would not be so statistically negative if the workers were prepared to see their own work in the light of being one of many contributing causes in a changing causal matrix rather than 'the cause' of a pathological unstable entity.-Emery 1983:132(1)

For infants between the ages of one month and one year, sudden infant death syndrome (SIDS), often referred to as cot or crib death, remains the major cause of death. Recognized as a distinct medical entity only as recently as 1963 at the first international SIDS conference, the syndrome continues to be defined as "the sudden death of an infant or young child, which is unexpected by history, and in which a thorough postmortem examination fails to demonstrate an adequate cause of death" (Beckwith, in Bergman, Beckwith, and Ray 1970:18; Wedgewood and Benditt 1965; Valdes-Dapena 1978; Barnett 1980).

Since that first meeting, scientists have cooperated in rigorous experimental and longitudinal studies of SIDS (Peterson 1983); yet even after 22 years of persistent and vigorous research, this syndrome still kills annually an estimated 10,000 infants, or approximately two out of 1,000 live births in the United States alone (Tildon, Roeder, and Steinschneider 1983). In the words of one investigator, whose research on the subject spans over 20 years, "There is not yet one positive criterion that can be employed by the clinician to identify the future victim, nor is there yet one positive criterion that the pathologist can use to recognize the subject at autopsy" (Valdes-Dapena 1980:4; Standfast, Jereb, Aliferis, and Janerich 1983). …